CN106849422A - A kind of four iron leg core cast-aluminum rotors, stator, motor with flume structure - Google Patents

Abstract

The invention discloses a four-section iron core cast aluminum rotor with a chute structure. The number of slots of the rotor is the same as that of the stator; the rotor includes a rotor core, a rotating shaft and guide bars; The tank body is skewed, and the guide bar is cast in the tank body of the iron core; the iron core includes two sections of the second iron core and the third iron core located in the middle; it is divided into the first iron core and the fourth iron core located at both ends. Iron core: the first iron core and the second iron core, the third iron core and the fourth iron core, the two grooves opposite to each other are twisted in a herringbone shape; between the second iron core and the third iron core There is an intermediate ring; the two slots opposite to each other in the second iron core and the third iron core are misaligned and reversely skewed; the bottom of the slots is a bifurcated structure; the invention also discloses a stator matched with the above-mentioned rotor and the motor. The invention has the advantages of effectively weakening the tooth harmonics, reducing synchronous additional torque and reducing the additional loss of the motor.

Description

A four-section iron core cast aluminum rotor, stator, and motor with a chute structure

technical field

The invention relates to the technical field of electromagnetic devices, in particular to a four-segment iron core cast aluminum rotor with a chute structure, a stator and a motor.

Background technique

The additional loss of the induction motor is mainly caused by the air-gap harmonic flux. These harmonic fluxes produce high-frequency losses (surface loss and tooth pulse loss) in the stator and rotor cores, and high-frequency current losses in the cage rotor, among which the harmonic flux of the stator and rotor teeth is the most significant. .

When the number of stator and rotor slots is equal, the potentials induced by the harmonic flux of the stator teeth in the adjacent bars of the rotor are equal in magnitude and phase, so no current will be generated between them, which indicates that when the slots are matched, the stator Tooth harmonic flux does not generate high frequency current losses in the rotor. At the same time, the width of the rotor tooth top is equal to the wavelength of the stator tooth harmonic, so the pulse vibration caused by the stator tooth harmonic flux in the rotor tooth is the smallest, and the pulse vibration loss is also the smallest.

When selecting the induction motor slot fit, from the perspective of reducing additional loss, the number of stator and rotor slots should be as close as possible. From the above description, it can be seen that when the number of stator and rotor slots is the same, the value of additional loss is the smallest, but equal slot fit is the motor A no-no in design, as this would cause synchronous additional torque at zero speed, making the motor unable to start.

The full-load additional loss of the induction motor is as high as 2% to 6%, which has a great impact on the efficiency of the motor. If the starting problem of the equal-slot fit can be solved and the equal-slot fit is used, the additional loss of the motor at full load can be greatly reduced and the efficiency of the motor can be improved.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a four-section iron core cast aluminum rotor, stator and motor with a chute structure that can effectively weaken tooth harmonics, reduce synchronous additional torque, and reduce additional loss of the motor.

The present invention solves the above-mentioned technical problems through the following technical means: a four-section iron core cast aluminum rotor with a chute structure, the number of slots of the rotor is the same as that of the stator; the rotor includes a rotor core, a rotating shaft, guide bar; the rotor core is set on the rotating shaft; the groove body of the iron core is skewed, and the guide bar is cast in the groove body of the iron core; the iron core consists of two sections located at The second iron core and the third iron core at the position between them; they are divided into the first iron core and the fourth iron core located at both ends; the first iron core and the second iron core, the third iron core and the The two opposite grooves in the fourth iron core are oppositely twisted to form a herringbone; an intermediate ring is arranged between the second iron core and the third iron core; the second iron core and the third iron core The two opposite slots in the third iron core are dislocated and reversely skewed; the bottom of the slots has a bifurcated structure.

Preferably, the stagger angle between the two opposite slots of the second iron core and the third iron core is half of the rotor slot pitch angle.

A stator matched with the above-mentioned rotor, the rotor is installed in the stator; the number of slots of the stator and the rotor is equal; the teeth of the stator are provided with arc-shaped grooves.

A motor, comprising a casing, a stator, a cast aluminum rotor, and a rotating shaft; the stator is arranged in the inner cavity of the casing, the cast aluminum rotor is built into the stator and fixedly mounted on the rotating shaft ; The rotating shaft runs through the housing and is connected to the housing in rotation;

The number of slots of the rotor is the same as that of the stator; the teeth of the stator are provided with arc-shaped grooves; the rotor includes a rotor core, a rotating shaft, and guide bars; the rotor core is sleeved on the rotating shaft The groove body of the iron core is skewed, and the guide bar is cast in the groove body of the iron core; it is characterized in that: the iron core includes two sections of the second iron core located in the middle position, the first Three iron cores; divided into a first iron core and a fourth iron core located at both ends; the first iron core is opposite to the second iron core, the third iron core and the fourth iron core The two tanks are reversely twisted to form a herringbone; an intermediate ring is arranged between the second iron core and the third iron core; the two opposite positions of the second iron core and the third iron core The slots are misaligned and twisted backwards; the bottom of the iron core slots has a bifurcated structure.

Preferably: the material of the intermediate ring includes aluminum.

Preferably: the staggered angle between the two opposite slots of the second iron core and the third iron core is an angle occupied by half of the slot pitch of the rotor.

Preferably, the angle between the two opposite slots of the second iron core and the third iron core is half of the slot pitch angle of the rotor.

Preferably: the skew pitch of the rotor is half of the slot pitch of the stator.

The advantage of the present invention is that: using a skewed rotor with a bifurcated bottom structure and connecting multiple "herringbone"-shaped rotors in series can form a "wave"-shaped rotor, so that radial force waves occur in phase along the axis of the motor's length direction. Displacement, the average radial force along the axial direction is reduced, effectively weakening the tooth harmonics and reducing the synchronous additional torque, and solving the starting problem of equal slot matching; the stator and rotor are equal slot matching, the additional loss of the motor is minimized, and the efficiency is improved.

Description of drawings

Fig. 1 is a schematic diagram of the side structure of the rotor in the present invention.

Fig. 2 is a schematic diagram of the end face structure of the stator in the present invention.

Fig. 3 is a schematic diagram of the end face structure of the rotor in the present invention.

Fig. 4 is a graph showing the variation of motor starting torque within a stator tooth pitch in the present invention.

Fig. 5 is a schematic diagram of the structure of the intermediate ring in the present invention.

detailed description

In order to further describe the present invention, it is further described below in conjunction with embodiment.

Example 1

As shown in Figures 1 and 3, this embodiment discloses a four-section iron core cast aluminum rotor with a chute structure, and the number of slots of the rotor is the same as that of the stator. The rotor includes a rotor core, a rotating shaft and guide bars 2 . A rotor iron core is sleeved on the rotating shaft. The slot body 1 of the iron core is skewed, and the guide bar 2 is cast in the slot body 1 of the iron core. The iron core includes two sections of the second iron core 32 and the third iron core 33 located between them. It is divided into a first iron core 31 and a fourth iron core 34 located at both ends. The two slot bodies 1 opposite to each other in the first iron core 31 and the second iron core 32 , and the third iron core 33 and the fourth iron core 34 are oppositely twisted to form a herringbone shape. An intermediate ring 4 is disposed between the second iron core 32 and the third iron core 33 . The two slot bodies 1 opposite to each other in the second iron core 32 and the third iron core 33 are dislocated and reversely twisted. The bottom of the tank body 1 has a bifurcated structure.

The invention has the following advantages: adopting the skewed rotor with a bifurcated bottom structure, and connecting multiple "herringbone" shaped rotors in series can form a "wave" shaped rotor, so that the radial force wave along the axis of the motor length direction Displacement, the average radial force along the axial direction is reduced, effectively weakening the tooth harmonics and reducing the synchronous additional torque, and solving the starting problem of equal slot matching; the stator and rotor are equal slot matching, the additional loss of the motor is minimized, and the efficiency is improved.

Example 2

As shown in FIG. 2 , a stator matched with the rotor of the above embodiment, the rotor is installed in the stator. The number of slots in the stator and the rotor is equal, and the teeth of the stator are provided with arc-shaped grooves 51 . The stator teeth are provided with arc-shaped grooves 51 to make the air-gap flux density more sinusoidal and reduce harmonic loss.

Example 3

As shown in Figure 1-3, a motor includes a casing, a stator, a cast aluminum rotor, and a rotating shaft. The stator is set in the inner cavity of the casing, and the cast aluminum rotor is built in the stator and fixedly installed on the rotating shaft. The rotating shaft runs through the shell and is rotatably connected with the shell. The stator teeth are provided with arc-shaped grooves 51 to make the air-gap flux density more sinusoidal and reduce harmonic loss.

The rotor has the same number of slots as the stator. The teeth of the stator are provided with arc-shaped grooves 51 . The rotor includes a rotor core, a rotating shaft and guide bars 2 . A rotor iron core is sleeved on the rotating shaft. The slot body 1 of the iron core is skewed, and the guide bar 2 is cast in the slot body 1 of the iron core. The iron core includes two sections of the second iron core 32 and the third iron core 33 located between them. It is divided into a first iron core 31 and a fourth iron core 34 located at both ends. The two slot bodies 1 opposite to each other in the first iron core 31 and the second iron core 32 , and the third iron core 33 and the fourth iron core 34 are oppositely twisted to form a herringbone shape. An intermediate ring 4 is disposed between the second iron core 32 and the third iron core 33 . The two slot bodies 1 opposite to each other in the second iron core 32 and the third iron core 33 are dislocated and reversely twisted. The bottom of the tank body 1 of the iron core has a bifurcated structure. The material of the intermediate ring 4 includes aluminum.

Example 4

An induction motor of Embodiment 3, its power is 5kW, the number of poles is 4, the outer diameter of the motor stator is 210mm, the length is 120mm, the number of slots is 36, and the stator teeth are provided with arc-shaped grooves 51 for modulating the air gap magnetic field. Table 1 shows the performance comparison of stator teeth with and without arc-shaped grooves.

Table 1

Stator teeth without arc grooves Stator teeth with curved grooves Distortion Rate of Air Gap Magnetic Density 40.3% 36.6% Distortion rate of current waveform 3.24% 2.93%

The number of slots of cast aluminum rotor is 36, the total length is 120mm, and the thickness d of the middle aluminum ring is 4mm. The segment is further divided into two sub-sections, each of which has a length of 29 mm, is symmetrical about the middle of each segment, and has a reverse oblique bsk=5.9 mm.

According to the harmonic magnetic field analysis, if the stator harmonic v _b and the rotor harmonic μ _a (produced by another stator harmonic) have the same order and direction, the two will generate synchronous additional torque when the speed is 0, so that the starting The torque fluctuates or dead point, and the motor cannot start. Due to the large amplitude of the stator and rotor tooth harmonics, the synchronous additional torque is mainly determined by the stator/rotor tooth harmonics. When equal grooves are matched, the orders of stator and rotor tooth harmonics are the same, the synchronous additional torque is the largest, and the motor cannot be started. After using the special skewed rotor, the rotor tooth harmonics of different segments can effectively cancel each other, which greatly eliminates the rotor tooth harmonics. At this time, the value of the rotor tooth harmonics is very small, and the synchronous additional torque generated by the stator tooth harmonics The value of is also very small, and the influence on the starting torque of the motor can be ignored at this time, so the motor can start normally. As shown in Figure 4, the rated torque of the motor is 36N·m, the minimum value of the starting torque is 81N·m, the maximum value is 139.6N·m, and the average value is 107N·m. It can be seen that the minimum starting torque multiple of the motor is 2.25, the maximum starting torque multiple is 3.88, and the average starting torque multiple is 2.97. Fully meet the requirements of motor starting.

The bottom of tank 1 of the iron core has a bifurcated structure, which can increase the skin effect during starting and improve the starting performance. Table 2 shows the performance comparison before and after using the bifurcated structure tank.

Table 2

Ordinary groove bifurcation structure slot Average starting torque 103N·m 104.7N·m Average starting current 76A 74.3A

It can be seen from the results that the motor of the present invention can completely solve the problem of starting the motor when the equal slots are matched, so that the equal slots can be used to reduce the additional loss of the motor.

According to the analysis of the harmonic magnetic field, the phases of the tooth harmonics of the rotors in each section are just opposite, and the harmonic torques generated by the tooth harmonics in each section cancel each other out, thereby achieving the purpose of reducing vibration and noise. Compared with the straight groove, the value that the sound power of the motor of the present invention can be reduced is about

ΔL=20lg[K _sk cos(uα/2)]

In the formula, K _sk is the chute coefficient, μ is the order of the harmonic magnetic field, and α is the rotor stagger angle.

After adopting the "wave" shaped skewed rotor, the noise reduction value compared with the straight slot is shown in Table 3 below.

table 3

1st order tooth harmonic 2nd Order Tooth Harmonic Sound pressure level reduction value (dB) 13.2 11.3

It can be seen that the induction motor of the present invention can significantly reduce noise.

As shown in FIG. 5 , the intermediate ring of the present invention may include an outer aluminum ring and an inner silicon steel ring 42 . The aluminum ring is provided with cast aluminum through-slots 411 , and several cast-aluminum through-slots are equidistantly distributed in a ring structure; the area between two adjacent cast-aluminum through-slots forms grooved ribs 412 . The plurality of cast aluminum through-slots 411 form slotted ribs 412 with the same number as the cast aluminum through-slots 411, and the number of slotted ribs 412 is a divisor of the number of rotor slots.

Preferably, the cast aluminum through-slot 411 has a fan-shaped structure, and several cast-aluminum through-slots are equidistantly distributed to form an annular structure concentric with the center of the damping ring. The intermediate ring of the present invention can also be a traditional aluminum ring.

Each iron core of the present invention is preferably integrally formed. First stack the first iron core 31, the second iron core 32, and then stack the intermediate ring 4, and then stack the third iron core 33 and the fourth iron core 34 in order to ensure that the grooved ribs and the iron The core tank body is misaligned. When casting aluminum, the aluminum water is injected from the end of the first iron core 31, and after passing through the second iron core 32, the aluminum water passes through the fan-shaped cast aluminum channel of the concentric aluminum ring of the intermediate ring 4 and enters the third iron core 33, the second Four iron cores 34, after the casting is completed, aluminum water fills the fan-shaped cast aluminum of the concentric aluminum ring to form a complete aluminum ring, connects the guide bars of each section of the rotor into a whole, and forms a cast aluminum end ring at the end of the whole , the casting of multi-section rotors can be completed at one time. Of course, the rotor of the present invention can also be cast in sections and then welded.

The outer diameter of the damping ring is consistent with the outer diameter of the rotor. The width of the grooved rib is about 2-4mm, which is used to connect the inner and outer rings supporting the concentric aluminum ring. The thickness of the inner and outer rings of the concentric aluminum ring is 1-3mm, and the thickness of the inner aluminum ring The inner diameter is consistent with the outer diameter of the silicon steel ring and is smaller than the distance between the bottoms of two rotor grooves which are symmetrical about the center of the rotor. The inner diameter of the silicon steel ring is equal to the diameter of the rotating shaft.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (8)

1. a kind of four iron leg core cast-aluminum rotors with flume structure, the slot number of the rotor is identical with the slot number of stator；It is described Rotor includes rotor core, rotating shaft, sliver；The rotor core is set with the rotating shaft；The cell body of the iron core is in skew Shape, the sliver is cast in the cell body of the iron core；It is characterized in that：The iron core include two sections be located between position the Two iron cores, the 3rd iron core, the first iron core, the 4th iron core for being located at two ends respectively；First iron core and second iron core, institute The 3rd iron core two cell body reverse skews relative with position in the 4th iron core are stated in herringbone；Second iron core and institute State and be provided with middle ring between the 3rd iron core；Second iron core, the two cell bodies dislocation relative with position in the 3rd iron core Reverse skew；The bottom of the cell body is in bifurcation structure.

2. a kind of four iron leg core cast-aluminum rotors with flume structure, it is characterised in that：Second iron core and the three-iron Two relative cell body offset angulars of position are half rotor slot-pitch angle in core.

3. a kind of stator that rotor with described in claim any one of 1-2 is engaged, rotor is installed in the stator；It is described Stator and rotor slot number are equal；It is characterized in that：The teeth portion of the stator is provided with arc groove.

4. a kind of motor, including casing, stator, cast-aluminum rotor, rotating shaft；The stator is arranged on the internal cavities of the casing In, the cast-aluminum rotor is built in the stator and is fixedly mounted in the rotating shaft；The rotating shaft runs through the shell, with The shell rotates connection；

Characterized in that, the slot number of the rotor is identical with the slot number of stator；The teeth portion of the stator is provided with arc groove；It is described Rotor includes rotor core, rotating shaft, sliver；The rotor core is set with the rotating shaft；The cell body of the iron core is in skew Shape, the sliver is cast in the cell body of the iron core；It is characterized in that：The iron core include two sections be located between position the Two iron cores, the 3rd iron core；Respectively positioned at the first iron core, the 4th iron core at two ends；First iron core and second iron core, institute The 3rd iron core two cell body reverse skews relative with position in the 4th iron core are stated in herringbone；Second iron core and institute State and be provided with middle ring between the 3rd iron core；Second iron core, the two cell bodies dislocation relative with position in the 3rd iron core Reverse skew；The bottom of the iron core cell body is in bifurcation structure.

5. a kind of motor according to claim 4, it is characterised in that the material of the middle ring includes aluminium.

6. a kind of motor according to any one of claim 4 or 5, it is characterised in that second iron core and the described 3rd The angle that two relative cell bodies of position stagger in iron core is half rotor slot away from shared angle.

7. a kind of motor according to claim 6, it is characterised in that second iron core and position in the 3rd iron core Two relative cell body offset angulars are 5 °.

8. a kind of motor according to claim 6, it is characterised in that the skewed slot of the rotor away from for half stator slot away from.